Deposition of thin films on a substrate surface is an important process in a variety of industries including semiconductor processing, diffusion barrier coatings and dielectrics for magnetic read/write heads. In the semiconductor industry, in particular, miniaturization requires atomic level control of thin film deposition to produce conformal coatings on high aspect structures. One method for deposition of thin films with control and conformal deposition is atomic layer deposition (ALD), which employs sequential, surface reactions to form layers of precise thickness. Most ALD processes are based on binary reaction sequences which deposit a binary compound film. Because the surface reactions are sequential, the two gas phase reactants are not in contact, and possible gas phase reactions that may form and deposit particles are limited. Another method for deposition of films is chemical vapor deposition, in which two or more reagents are co-flowed to deposit a film over a substrate.
Silicon is a very important component in semiconductor processing. Currently no process exists for the deposition of silicon-containing materials (e.g., SiCN, SiN, SiBN, SiON, etc.) at low temperatures (i.e., less than about 400° C.) without the use of plasma co-reagents. This is because most silicon precursors have limited-reactivity towards chemisorption and/or common co-reagents, such as NH3, O2, H2O. Furthermore, even if a silicon precursor has the requisite reactivity, it can be crucial to have quick reactions during half reaction cycles of ALD, or the growth rate will be too low to be practical for commercial applications. Additionally, while there are known silicon ALD/CVD precursors that contain halides, these can be problematic, as the halides can undesirably end up in the deposited film.
Accordingly, there is a need for new chemistries and methodology for the deposition of silicon-containing films which addresses one or more of the problems described above.